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The use of selected commercial molecular assays for the microbiological diagnosis of tuberculosis
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Abstract
Introduction: We performed a retrospective assessment of the AMPLICOR Mycobacterium tuberculosis (MTB) assay for the molecular diagnosis of tuberculosis based on our own determinations between 1999 and 2009 and a preliminary assessment of the Xpert MTB/RIF system, which we are currently using.
Materials and methods: The study groups comprised 1875 samples (including 104 inhibited samples) and 213 samples, respectively.
Results: The sensitivities of the AMPLICOR MTB and the Xpert MTB/RIF assays were 81.9% and 81.8%, respectively, and their specificities were 97.2% and 99.5%, respectively, versus culture on Loewenstein-Jensen medium. Both assays showed a considerable difference in sensitivity depending on whether the test samples were smear-positive (AFB+) or smearnegative (AFB–). The sensitivities of the AMPLICOR MTB and the Xpert MTB/RIF assays were 97.8% and 100.0%, respectively, for AFB+ samples and 58.1% and 50.0%, respectively, for AFB– samples. Conclusions: Our results confirm full usefulness of the Xpert MTB/RIF assay for routine diagnosis in the case of smearpositive clinical samples.
Abstract
Introduction: We performed a retrospective assessment of the AMPLICOR Mycobacterium tuberculosis (MTB) assay for the molecular diagnosis of tuberculosis based on our own determinations between 1999 and 2009 and a preliminary assessment of the Xpert MTB/RIF system, which we are currently using.
Materials and methods: The study groups comprised 1875 samples (including 104 inhibited samples) and 213 samples, respectively.
Results: The sensitivities of the AMPLICOR MTB and the Xpert MTB/RIF assays were 81.9% and 81.8%, respectively, and their specificities were 97.2% and 99.5%, respectively, versus culture on Loewenstein-Jensen medium. Both assays showed a considerable difference in sensitivity depending on whether the test samples were smear-positive (AFB+) or smearnegative (AFB–). The sensitivities of the AMPLICOR MTB and the Xpert MTB/RIF assays were 97.8% and 100.0%, respectively, for AFB+ samples and 58.1% and 50.0%, respectively, for AFB– samples. Conclusions: Our results confirm full usefulness of the Xpert MTB/RIF assay for routine diagnosis in the case of smearpositive clinical samples.
Keywords
amplifikacja kwasów nukleinowych; gruźlica; reakcja łańcuchowa polimerazy w czasie rzeczywistym
About this articleTitle
The use of selected commercial molecular assays for the microbiological diagnosis of tuberculosis
Journal
Advances in Respiratory Medicine
Issue
Pages
6-12
Published online
2011-12-21
Bibliographic record
Pneumonol Alergol Pol 2012;80(1):6-12.
Keywords
amplifikacja kwasów nukleinowych
gruźlica
reakcja łańcuchowa polimerazy w czasie rzeczywistym
Authors
Aleksandra Safianowska
Renata Walkiewicz
Patrycja Nejman-Gryz
Hanna Grubek-Jaworska